1. Field of the Invention
The present invention pertains generally to a mill for the manufacture of continuous seam-welded tubes or pipes, and more particularly to an automated system for rapidly changing such a mill from the production of one size of shape of tube to production of tube of another and different size or shape.
2. Description of the Prior Art
In accordance with a well known process for producing seam-welded tubes, a continuous strip or skelp is advanced through forming apparatus comprising a series of forming rolls and progressively deformed into a tubular form having an open, longitudinally extending seam. The tubular form then advances through a welding station wherein the adjacent longitudinal edges are urged together and joined by a suitable welding process. The welded tube may then have the raised weld bead removed from its surfaces and, after passing through a cooling zone, pass through a series of shaping and sizing rollers whereby it is formed to the final configuration and size. The advancing continuous tube is then severed by means of a travelling cutting unit into individual sections of a predetermined length.
The machines are designed to be capable of conversion to production of various sizes and cross-sectional configurations of tubes and pipes. As will be readily appreciated, such machines are massive precision machines representing a considerable capital investment. Heretofore in converting from production of tubing of one size or shape to another, the line was shut down and the various components were individually removed and replaced by components required for production of the next product. The replacement components then had to be properly set and adjusted on the line before production could resume. This entire changeover routine could consume a considerable period of time, typically five or six hours or more. The changeover thus involves a considerable expenditure in time and money, and an extensive loss of production. As a result, it becomes necessary to maintain unduly large inventories of finished products, contrary to the current trend toward maintaining minimum inventory and frequently switching from production of one product to another.